Fuji Xerox Co., Ltd.

Shigeto Hashiba

Kenta Ide

Satoya Sugiura

Kazuhiro Koseki

Hirofumi Nakamura

Akihiro Kawasaki

Takahiro Suzuki

Hidemi Nukada

Kosuke Narita

Fuyuki Kano

Akihiro Nonaka

Koji Bando

Takashi Imai

Takeshi Iwanaga

Kiyoshi Hashimoto

Tomoya Sasaki

Masaki Hirakata

Masahiko Miyamoto

Kazuyuki Nakamura

Nobuyuki Ichizawa

Hiroshi Miyamoto

Daisuke Haruyama

Yoshiyuki Ono

Makoto Takemoto

Nobuyuki Torigoe

Ichiro Takegawa

Hideya Katsuhara

Sadao Okano

Seiji Ashiya

Masanori Murase

Masahiko Hodumi

Kaori Iemura

Hirofumi Kawashima

Toshiaki Takahashi

Yasuo Furusawa

Yuusuke Harada

An electrophotographic photoreceptor includes a conductive substrate satisfying a condition (A); an undercoat layer satisfying conditions (B) and (C), disposed on the conductive substrate, and containing metal oxide particles; and a photosensitive layer disposed on the undercoat layer: condition (A): in the case where depressions existing in the surface of the conductive substrate are observed with a laser microscope, the width of the largest depression is 400 &#x3bc;m or less, and the depth of the depression is 15 &#x3bc;m or less; condition (B): in the case where the undercoat layer is subjected to a Cole-Cole plot analysis, an angular frequency &#x3c9;max at which a complex impedance component is maximum is from 2.0 rad to 25.0 rad; and condition (C): volume resistivity obtained from the Cole-Cole plot analysis of the undercoat layer is from 7.0&#xd7;10&#x3a9; to 1.0&#xd7;10&#x3a9;.

Electrophotographic photoreceptor, process cartridge, and image forming apparatus

An electrophotographic photoreceptor includes a conductive substrate; an organic photosensitive layer that is provided on the conductive substrate; and an inorganic protective layer that is provided on the organic photosensitive layer so as to be in contact with a surface of the organic photosensitive layer, wherein the organic photosensitive layer includes at least a charge transport material and silica particles in a region on the surface side in contact with the inorganic protective layer.

An electrophotographic photoreceptor includes a cylindrical conductive substrate, an undercoat layer containing a cured product of a resin and a blocked isocyanate and being disposed on the conductive substrate, and a photosensitive layer on the undercoat layer. The degree of curing of the undercoat layer defined by the equation below is about 1.5 or less in both a region A and a region B defined below: Region A (B): A region between a position distant from a first (second) end of the conductive substrate by about &#x215b; of a length of the conductive substrate and a position distant from the first (second) end of the conductive substrate by about &#x2155; of the length of the conductive substrateDegree of curing=[Amount () of blocking agent separated from blocked isocyanate in undercoat layer]/weight of undercoat layer ()&#xd7;100.

An electrophotographic photoreceptor includes a conductive support, an undercoat layer that is provided on the conductive support and that has a thickness of from 15 &#x3bc;m to 40 &#x3bc;m and has light transmittance of 20% or less with respect to light having a wavelength of 450 nm when the thickness is at least 15 &#x3bc;m, a charge generation layer that is provided on the undercoat layer, and a charge transport layer that is provided on the charge generation layer and that has a thickness of from 15 &#x3bc;m to 40 &#x3bc;m and has light transmittance of 30% or less with respect to light having a wavelength of 450 nm when the thickness is at least 15 &#x3bc;m.

An image forming apparatus includes at least an electrophotographic photoreceptor having at least a conductive support, an undercoat layer, and a photosensitive layer; a charging device that charges the surface of the electrophotographic photoreceptor in a contact charging mode, in which only DC voltage is applied; an electrostatic latent image forming device that exposes the surface of the charged electrophotographic photoreceptor to form an electrostatic latent image; a developing device that develops the electrostatic latent image by a developer to form a toner image; and a transfer device that directly transfers the toner image from the electrophotographic photoreceptor to a transfer medium; and does not include an erasing device for erasing the surface of the electrophotographic photoreceptor after the toner image is transferred onto the transfer medium by the transfer device and before the surface of the electrophotographic photoreceptor is charged by the charging device.

Image forming apparatus and process cartridge

An electrophotographic photoreceptor includes a conductive support, and an undercoat layer, a charge generation layer, and a charge transport layer that are provided in this order on the conductive support, wherein the undercoat layer includes at least metallic oxide particles, a reactive acceptor substance including an anthraquinone structure expressed by the following Formula 1, and a binder resin, the charge generation layer includes hydroxygallium phthalocyanine as a charge generation material, and a reflectance of incident light having a wavelength of 780 nm on a surface of the charge generation layer when the charge transport layer is removed is 17% or greater: wherein the anthraquinone structure expressed by Formula 1 is bonded to another structure at a position of *, and thus forms the reactive acceptor substance, and in Formula 1, n1 represents an integer of 1 to 7.

An electrophotographic photoreceptor includes a support; an undercoat layer which is provided on the support and contains at least a binder resin, metal oxide particles, and an electron-accepting compound having an anthraquinone structure, in which a content of the electron-accepting compound is from 0.5% by weight to 1.5% by weight with respect to the metal oxide particles and a contact angle of the metal oxide particles with respect to water is from 7&#xb0; to 12&#xb0;; and a photosensitive layer which is provided on the undercoat layer.

Electrophotographic photoreceptor, image forming apparatus, and process cartridge

An electrophotographic photoconductor includes a base, an undercoat layer that contains a metal oxide and an electron-accepting material and has a thickness of about 3 &#x3bc;m or more and about 15 &#x3bc;m or less, and a photosensitive layer containing a polymer having a repeating unit represented by general formula (1) where Rand Reach independently represent a halogen atom, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, or an aryl group having 6 to 12 carbon atoms; and m and n each independently represent an integer of 0 to 4.

Electrophotographic photoconductor, process cartridge, and electrophotographic image-forming apparatus

An electrophotographic photoreceptor, includes: a conductive support; and a photosensitive layer provided on or above the conductive support, the photosensitive layer including an outermost surface layer at the farthest location from the conductive support, wherein the outermost surface layer contains: coated insulating inorganic particles obtained by subjecting insulating inorganic particles having a specific surface area of not more than about 300 m/g to a coating treatment with an aromatic functional group-containing compound; and fluorine-containing organic particles.

Electrophotographic photoreceptor, process cartridge and image forming apparatus

A charging roller including: a support; an elastic layer provided on the outer peripheral surface of the support, and having a ground-finished outer peripheral surface; and a surface layer formed to cover the outer peripheral surface of the elastic layer and that has a thickness of about 2 &#x3bc;m to about 10 &#x3bc;m from the outer peripheral surface of the elastic layer, and a proportion of water absorbed in the total of the elastic layer and the surface layer, after storage for 48 hours in an environment having a temperature of 10&#xb0; C. and a humidity of 15% RH, and after storage for 48 hours in an environment having a temperature of 28&#xb0; C. and a humidity of 85% RH, being about 2% to about 8% by weight, being about 2% to about 8% by weight.

Charging roller, electrophotographic process cartridge, and image forming apparatus

A dip coating method, in which a cylindrical member is dipped in a coating solution in a coating solution tank and the coating solution is coated on an outer peripheral surface of the cylindrical member by the cylindrical member being raised, includes the steps of: making the coating solution always overflow from the coating solution tank; dipping the cylindrical member into the coating solution through an opening portion of a cover which is provided above a surface of the coating solution in the coating solution tank, and which has the opening portion through which the cylindrical member can pass, and which has a plurality of plates which are disposed at intervals in a vertical direction; and raising the cylindrical member.

Dip coating apparatus for manufacturing electrophotographic photoreceptor

A process for the preparation of an electrophotographic photoreceptor having a high sensitivity and stability and an excellent product quality stability without being affected by the production environment is disclosed, which comprises coating on a substrate a functional layer-forming coating solution containing a compound which undergoes polycondensation upon hydrolysis, adjusting a temperature of said substrate having the coated layer such that relationship (1) is satisfied, and then moistening said coated layer at a temperature of 30.degree. C. to 180.degree. C. in an atmosphere of a dew point of 25.degree. C. to 80.degree. C.:

Process for producing electrophotographic photoreceptor

An abrasive suspension for wet honing for surface treatment of an electrically conductive substrate for an electrophotographic photoreceptor, the suspension comprising pure water having suspended therein at least 20% by weight, based on the total weight of the abrasive suspension, of an abrasive and having an electrical conductivity of not more than 10 .mu.s/cm. A conductive substrate having its surface roughened by using the abrasive suspension is free from impurities.

Abrasive suspension for wet honing and surface treating method using the

A novel electrophotographic photoreceptor is disclosed, comprising an undercoating layer provided on an electrically conductive substrate having thereon a light-sensitive layer, wherein the undercoating layer is obtained by coating a solution of a composition comprising zirconium and silicon or a solution of a mixture of a zirconium acetyl acetonate compound and a silane coupling agent, the silicon content in the composition comprising zirconium and silicon is in the range of 5 to 35 mol % based on the total amount of zirconium and silicon, and the hardened undercoating layer obtained from the zirconium acetyl acetonate compound and silane coupling agent is a layer having a hardening degree of 1.2 or less.

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Kanagawa, Japan

Shigeto Hashiba